Ham canning method



2 Sheets-Sheet 1 Filed Sept. 16, 1959 fig .1.

Dec. 17, 1963 s. A. PETERSON HAM CANNING METHOD 2 Sheets-Sheet 2 FiledSept. 16, 1959 fig. .7.

United States Patent 3,114,644 HAM CANNING METHOD Stanley ArthurPeterson, Rochester, Minn, assignor to American Can Company, New York,N.Y., a corporation of New Jersey Filed Sept. 16, 1959, Ser. No. 840,3171 Claim. (Cl. 99-187) The present invention relates to canning methods,and has particular reference to a method of pressing whole hams orsimilar irregularly shaped chunks of meat into can bodies.

Reference is made to copending application Serial No. 840,318, filedSeptember 16, 1959, now Patent 3,001,343, in the names of James HenryGordon, Stanley Arthur Peterson and George Martin Stone and assigned tothe instant assignee, which application is entitled Canning Machine andcovers a machine wherein the method of the instant invention may beeifectuated.

The cans ordinarily used for the canning of whole hams are generallyformed with vertical tubular side walls having fiat top and bottom endssecured thereto in conventional double seams. The cans are formed invarious heights in order to accommodate variations in the size of thehams and are substantially ovate in horizontal crosssection. The hamsthemselves are quite irregular in shape, ranging from almost sphericalto ellipsoidal or ovate and often have surface indentations orirregularities. Consequently, they do not readily fit completely intothe can when they are first placed therein. Thus, it is necessary toforce the ham into the can under substantial pressure in order to makeit conform to the shape of the can.

It frequently happens that the shape of the ham is such that when it isinserted into the can, large air-filled spaces are initially present atthe bottom of the can around the ham. Frequently too, the surfaceindentations of the ham are positioned at the bottom of the can. Whenthe ham is then pressed into the can, usually by means of ahydraulically operated pressure plate which engages the upper side ofthe ham, the meat moves outwardly against the side wall of the can,sealing off the air between the ham and the can at the bottom of the canand in the surface indentations of the ham and preventing its escape.This entrapped air is compressed as the meat is forced downwardly by thepressure plate, thus preventing the ham from completely filling the can,and entrapped air expands somewhat when the pressure is relieved, thuscausing the ham to move upwardly in the can. As a result, it isfrequently necessary to use a can body of somewhat greater height thanwould otherwise be necessary to contain the volume of the ham.

The upward movement of the ham is generally insufiicient to break theseal around the entrapped pockets of air, and thus the air remains inthe can body, even though it is later closed under vacuum, with theresult that the adjacent areas of the meat are discolored by thechemical reaction which takes place between the oxygen in this entrappedair and the ham after the can has been sealed.

The present invention overcomes these problems by utilizing the step ofsubjecting the can with the loosely fitting ham therein to a vacuumprior to the time pressure is applied to the ham to force it to take theshape of the can. As a result of this air evacuating step, the formationof air pockets is avoided, with the result that the harm is permitted toconform much more closely to the interior contour of the can and theundesirable oxidation discoloration is thus eliminated.

An object of the present invention therefore is the provision of amethod of pressing hams wherein the entrapment of air at the bottom ofthe can is avoided.

3,114,644 Patented Dec. 17, 1963 Another object is the provision of amethod of pressing whole hams which results in the formation of bettershaped hams.

A further object is the provision of a method of pressing ham whichresults in material savings by reason of the fact that it permits theuse of smaller height cans, since the cans are more solidly filled thanheretofore.

Still another object is the provision of a method of pressing whole hamswherein the unsightly discoloration of surface portions of the hams inthe subsequently sealed and processed cans is prevented by theelimination of air pockets beneath the pressed hams.

Numerous other objects and advantages of the invention will be apparentas it is better understood from the following description, which, takenin connection with the accompanying drawings, discloses a preferredembodiment thereof.

Referring to the drawings:

FIGURE 1 is a vertical section taken through the vacuum chamber of a hampressing machine wherein the process of the instant invention is beingperformed, the view showing the air being withdrawn from a can bodywhich contains a ham which fits loosely therein;

FIG. 2 is a view similar to FIG. 1, but illustrating the subsequent stepof pressing the ham into contact with the interior walls of theevacuated can body; and

FIG. 3 is a view in horizontal section taken substantially along theline 33 of FIG. 1, and emphasizing how the ham is initially placed inthe can body so that passageways leading to the potential air pockets atthe bottom of the can are created.

As a preferred and exemplary embodiment of the instant invention, thedrawings illustrate the instant method of pressing a whole, boned ham 10into a can body 12. As seen in FIGS. 1 and 3, the ham 10, prior to thepressing operation, is irregular in shape. In practice, the hams beingpacked are never exactly the same in shape. The variations in shape arelimitless, but in general it can be said that their shapes range fromalmost round to almost spheroidal or ovate. The hams are irregular insurface contour, sometimes being formed with deep or shallow surfaceindentations, and often are quite eccentric or lop-sided in shape.

The can body 12 is formed with a vertical side wall 14 which issubstantially ovate in horizontal cross-section as best seen in FIG. 3,and is formed with a vertical side seam (not shown) in the usual manner.At its upper end, the side wall 14 is formed with an outwardly extendingperipheral flange 16. A flat bottom end 18 is secured to the lower endof the body 12 in a conventional double seam 20.

As the first step of the instant invention, the ham is carefully placedloosely in position in the container body 12 in such a manner that oneor more vertical open passageways 21 surrounding the ham lead from theupper, open end of the can to its closed bottom end, so that the largeair spaces 22, which are present in the bottom corner portions of thecan because of the difference in shape between the ham and the can body,are not sealed off by the engagement between the ham and the can sidewall 14.

After the ham 10 has been thus positioned in the can body 12, the canbody 12 is subjected to a strong vacuum in order to remove all of theair which is present Within the body. This is preferably done bypositioning the filled can body 12 within a vacuum chamber 23 which isformed by a bell or housing 24, the lower end of which carries a sealinggasket 26 which engages against a horizontal plate 28. The plate 28 ispreferably formed with a raised locating platform 30 which snugly fitswithin the bottom double seam 20 and flatly engages against theundersurface of the can end 18.

The bell 24 and the plate 28 are vertically movable relative to eachother to permit the insertion and removal of the can body 12 and the ham10 contained therein.

The vacuum is drawn on the interior of the chamber 23 through a vacuumpipe 32 which is connected to any suitable source of vacuum, such as avacuum tank or pump (not shown). Because of the existence of thepassageways 21, the spaces 22 at the bottom of the can body 12 are incommunication with the vacuum within the chamber 22 and the air issubstantially completely removed from within the can body 12. The canbody 12 need not be supported against collapse during the vacuumizingstep because the pressures on both sides of the body wall 14 isequalized.

After the air has thus been removed or exhausted from the can body 12and vacuum chamber 23, a flat presser plate 34 is moved downwardlyagainst the top of the ham 10 under sufficient pressure to force the hamto take the shape of the inside of the can body 12, as seen in FIG. 2.The presser plate 34 is mounted at the lower end of a rod 36 and issubstantially similar in outline to the cross-sectional shape of thebody 12, being only slightly smaller in its horizontal dimensions sothat it fits into the body without touching the body side wall 14. Therod 36 extends through an opening 38 formed in the top of the vacuumbell 24 and is preferably connected at its upper end to the piston of ahydraulic pressure cylinder (not shown) or other pressure means which iscapable of exerting a total pressure of at least 1000 lbs. against theham, when used in conjunction with a No. 4 base ham can.

As can be seen in FIG. 2, the evacuation of the air from the air spaces22 and passageways 21 prevents the formation of sealed air pockets inthe lower part of the can body 12, with the result that the ham ispressed into intimate contact with the side wall 14 and bottom end 18 ofthe can body 12. The barn thus conforms almost exactly to the interiorcontour of the can body 12, and waste space within the can body issubstantially eliminated.

During the application of pressure to the ham by the presser plate 34,the can body 12 is supported against bursting and/or deformation by apair of support molds 40 which move into intimate contact with the bodyside wall 14 prior to the pressing operation. The molds 40 contact theside wall 14 for substantially its full height above the bottom seam 20,and are provided with aligned grooves 42 which receive the outwardlyprojecting body flange 16. Each mold 40 is mounted for horizontalmovement on a rod 44 which is connected to any suitable actuating means,such as a hydraulically actuated piston (not shown), which moves themold 40 into contact with the body wall 14 and holds it in non-yieldingcontact 4 therewith to back up the body wall 14 against the pressureexerted by the presser plate 34. During the pressing operation, the canbottom end 18 is backed up by the raised platform 30.

At the completion of the pressing operation, the vacuum in the chamber22 is shut off and the chamber is opened to atmospheric pressure,preferably by means of a valve (not shown) located in the vacuum pipe32. The molds 40 and presser plate 34 are then retracted to theinoperative position of FIG. 1 and the bell 24 and plate 28 separated topermit removal of the filled can body 12.

Upon this release of the presser plate pressure, the ham expandsslightly, but is kept in close contact with the body walls by theatmospheric pressure which is exerted against its exposed upper surface.

After removal, the filled can body 12 is closed and its contents heatprocessed in the usual manner.

It is thought that the invention and many of its attendant advantageswill be understood from the foregoing description, and it will beapparent that various changes may be made in the steps of the methoddescribed and their order of accomplishment without departing from thespirit and scope of the invention or sacrificing all of its materialadvantages, the method hereinbefore described being merely a preferredembodiment thereof.

I claim:

The method of packing a chunk of a whole ham into an open can body so asto prevent the entrapping of air between the ham and can body whereinthe ham has an irregular contour relative to the can body interior,comprising the steps of:

arranging the ham loosely within the can body to provide opencommunication between the open end of the can body and areas within thecan body where the barn is spaced inwardly therefrom,

subjecting the interior of the can body to a vacuum to evacuate the airfrom said areas through the open can body end, thereby eliminating thepresence of air adjacent said ham throughout the can,

and pressing said ham into substantially intimate contact with theinterior of said can body without causing any substantial deformation ofthe can body while continuing said vacuumizing step to thereby preventthe trapping of air between said ham and said can body, wherebysubsequent discoloration of the ham by entrapped air is prevented.

References Cited in the file of this patent UNITED STATES PATENTS2,224,398 Komarik Dec. 10, 1940 2,696,442 Allbright Dec. 7, 19542,696,443 Allbright Dec. 7, 1954

